JPH07214661A - Device for sizing and supporting extruded tubular film blown up by film bubble - Google Patents

Abstract

PURPOSE: To provide an apparatus capable of preventing or reducing the vibration of the support bar for supporting a support segment even if the support segment is regulated to various diameters of a film bulb. CONSTITUTION: In an apparatus for calibrating and supporting an extruded tubular film blown up into a film bulb, the support means driven by link rods 12, 16 are provided and the inner end parts of the link rods are articulated in the median zone of each support means and the outer end parts thereof are articlated to brackets 11, 15 and screw spindles 7 are mounted on the basket-shaped frames 1, 2, 3. The screw spindles 7 are provided with threads of opposite hand screwed into spindle nuts 6 and additional link rods 16 parallel to the link rods are arranged and the respective end parts of the link rods 16 are articlated to the support bar and the bracket 15.

Description

Detailed Description of the Invention

[0001]

This invention relates to sizing of extruded tubular films blown up into film bubbles made from a synthetic resin melt in an expansion extruder.
A device for ibrating and supporting.

[0002]

2. Description of the Related Art German patent (DE-A-311780)
In the device known from 6), the lever for moving the bubble consists of two intersecting bars forming two scissor-shaped adjustment bars, the upper end of which is, on the one hand, a bush fixed to the frame. On the other hand, and on the other hand, to the upper end of each support bar. In this configuration, the outer lower end of one of the cross bars is attached to a spindle nut that is adjustable by a spindle drive,
The inner lower end of the other cross bar is attached to a bush that is displaceable on the support bar. This known method of making radial adjustment of a support bar that supports a support segment is used when increasing the inward adjustment of the support bar (ie when the support bar is set to a tubular film bubble with a small diameter). This results in an increase in the length of the unsupported free lower end of the support bar. Due to the elasticity of the support bars and the mass to which they are connected, the free ends of the support bars that support the support segments are more susceptible to vibration as the length of the unsupported free ends increases. This tendency to oscillate is further increased because the adjusting screw spindle (on which the spindle nut pivots the cross bar) is also mounted on only one side.

[0003]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a device of the type mentioned at the outset for a support bar which supports the support segment even when the support segment is adjusted to different diameters of the film bubble. It is an object of the invention to provide a device which can prevent vibrations or at least reduce it to an acceptable level.

[0004]

According to the present invention, there is provided an apparatus for sizing and supporting an extruded tubular film blown up into a film bubble made of a synthetic resin melt in an expansion extrusion device, the film bubble comprising: Has support means applied substantially tangentially thereto and forming a polygon approximating a circle, said support means comprising bars arranged parallel to the axis of the tubular film, each bar comprising: In a device articulated to the outer basket-shaped frame by a respective lever provided with an adjusting drive so that the can be displaced radially in these planes by the same amount, said lever comprising a link rod, The inner end of the link rod is articulated to the intermediate zone of each support bar, and the outer end supports the spindle nut at at least two locations. Is connected to a bracket forming a part of a frame, a basket-shaped frame is provided with a screw spindle parallel to the axial direction, the screw spindle is provided with driving means, and the screw spindle is screwed with the spindle nut. An additional link rod that is parallel to the link rod is disposed at a position at a constant distance from one of the link rods. A device is provided in which each end of is articulated to the support bar and the bracket, respectively. The link rods supporting the support bar always act on the intermediate zone of the support bar, even when making radial adjustments of the support bar. Thus, the support bar can be articulated to both link rods so as to prevent unacceptable vibrations. The vibration behavior of the support bar does not change as a result of the adjustment of the film bubbles to different diameters. This is because the joint connection point of the two link rods does not change even with this adjustment.

The two link rods supporting each support bar are connected to the support bar by a common articulation pin.
An additional link rod parallel to the one of the link rods is arranged at a position at a constant distance from one of the link rods, and an end portion of the link rod is the same as an end portion of the one link rod. Articulated to the support bar and bracket. The additional link rod preferably cooperates with the one link rod to form a parallelogram of the link rod. The additional link rods do not have the function of supporting the respective support bar, but merely the function of stabilizing the support bar and guiding the support bar in parallel.
The screw spindles are preferably mounted on a frame-shaped basket in the middle zone between their upper end, lower end and the oppositely threaded parts in order to suppress the possibility of screw spindle vibrations. The screw spindle is preferably mounted on a support parallel to the axial direction of the frame-shaped basket, which support forms the corners of the polygonal basket in plan view. The drive means of the screw spindle may consist of a sprocket which fits into the journal of the screw spindle projecting from the frame contour of the basket, on which the common drive chain runs.

Adjacent support link rods or support segments attached to the support bar are arranged so that they are offset from each other in a vertical or axial plane, respectively, so that the support link rods have a large adjustment movement without hindering each other. It is appropriate to be able to achieve.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. The lower octagonal frame 1 is fixed to the upper frame 3 (which is also octagonal) via eight vertical columns 2. Within the outline of these frames 1 and 3, two movable frames 4 and 5 arranged one above the other are provided, and these movable frames 4 and 5 also have an octagonal shape. For the purpose of adjusting these frames 4, 5, the screw spindle 7
A spindle nut 6 surrounding the frame is connected to the frame at several corners (at least two, preferably four in this embodiment). The screw spindle 7 is rotatably supported by both the lower frame 1 and the upper frame 3, and a sprocket 8 is connected to the upper end of each screw spindle 7, and all the sprockets 8 have a common drive chain 9. Are connected to each other via. In order to prevent the vibration of the screw spindle 7, the central portions of the four screw spindles are connected to the column 2 via the holder 10 adjacent to the column 2. The screw spindle 7 has opposite threads on both sides with respect to these central regions, so that when the sprocket 8 is driven, the frames 4, 5 are moved towards or away from each other.

In each of the eight corner areas, the frame 4 has a respective bracket 11, which is connected via a link rod 12 and a bracket 17 to approximately the center of the associated vertical holder 14. ing. Like the frame 4, the upper movable frame 5 also
Bracket 1 for each of the eight corner points
5 and each bracket 15 has a corresponding bracket 17 on the holder 14 via a twin link rod 16.
Are linked to. The vertical holder 14 carries the actual support segments 18 and these support segments 18
Is in the inward position in the left half and in the outward position in the right half of FIG. The longitudinal center extrusion axis is referenced 1
It is shown at 9. In FIG. 1, one of the link rods 12 and one of the twin link rods 16 that is adjacent to the link rod 12 has a common point in that the link rod 16 has a common point.
It is clearly shown that it is linked to 7. With this configuration, bending force is effectively prevented from acting on the vertical holder 14. The other link rod 16 of the twin link rods 16 (that is, the link rod on the side away from the adjacent link rod 12) serves only as a parallel guide for the holder 14.

For clarity, only four sets of support segments 18 are shown in FIG. The other support bars 14 to which the support segments are attached are also connected to these link rods 1.
It is supported by 2, 16 (only shown in cross section). However, the intervening support bars 14, not shown, lie in radial planes, which are offset relative to the set of support segments 18 shown, so that the support segments 18 shown and segments not shown are And do not interfere with each other in these adjustment movements.

[Brief description of drawings]

FIG. 1 is a side view showing a sizing basket.

FIG. 2 is a plan view showing the sizing basket of FIG.

FIG. 3 is an enlarged view showing a part of the sizing basket circled in FIG. 2.

[Explanation of symbols]

 1 Lower frame 2 Vertical column 3 Upper frame 4 Movable frame 5 Movable frame 6 Spindle nut 7 Screw spindle 8 Sprocket 9 Drive chain 10 Holder 11 Bracket 12 Link rod 14 Vertical holder 15 Bracket 16 Twin link rod 17 Bracket 18 Actual support Segment 19 Center extrusion axis

Claims (7)

[Claims] 1. An apparatus for sizing and supporting an extruded tubular film blown up into a film bubble made from a synthetic resin melt in an expansion extrusion device, the device being applied substantially tangentially to the film bubble and circular. With a support means forming a polygon approximating to, said support means comprising bars arranged parallel to the axis of the tubular film, each bar being radially identical in each of these planes. In a device articulated to an outer basket-shaped frame by a respective lever provided with an adjusting drive so that it can be displaced by a quantity, said lever comprising a link rod (12, 15) The ends are articulated to the intermediate zone of each support bar (14) and the outer ends support the spindle nut (6) at least at two points. Articulated to brackets (11, 15) forming part of the frame (4, 5) and attached to the basket-shaped frame (1, 2, 3) with axially parallel screw spindles (7), The screw spindle (7) is provided with a driving means, and the screw spindle (7) is provided with a screw portion formed with a screw in the opposite direction to be screwed with the spindle nut (6). An additional link rod (16) parallel to the link rod is arranged at a position at a constant distance from the link rod, and each end of the link rod (16) has the support bar (14) and the support bar (14) respectively. Device characterized in that it is articulated to said bracket (15). 2. Device according to claim 1, characterized in that the upper link rod (16) cooperates with the additional link rod (16) to form a parallelogram of the link rod. 3. The screw spindle (7) comprises a frame-shaped basket (1, 2 ,,) in an intermediate zone between its upper end, lower end and oppositely threaded parts.
Device according to claim 1 or 2, characterized in that it is attached to 3). 4. The screw spindle (7) is mounted on a support (2) parallel to the axial direction of the frame-shaped basket (1, 2, 3), the support being polygonal in plan view. 4. A device according to any one of the preceding claims, characterized in that it forms part of a basket. 5. A sprocket (8) in which the drive means of the screw spindle are fitted in the journal of the screw spindle (7) projecting from the frame contour (3) of the basket.
A device according to any one of the preceding claims, characterized in that a common drive pulling means (9) runs on the sprocket (8). 6. Adjacent support link rods or support segments attached to said support bar (14) are arranged offset from one another in a vertical or axial plane, respectively. The device according to any one of 1 to 5. 7. A device according to claim 1, wherein the support means forming the polygon comprises segments (18) with curved sides.